104 



(c) Injected Kidney. 



The kidney of a dog was injected with Berlin blue through the 

 renal artery, hardened in alcohol, stained in borax carmine, and 

 embedded in paraffin. Fix and mount in balsam. 



Study under low power, observing the injected inter- 

 lobular arteries. Note the glomeruli with their afferent 

 and efferent vessels, the capillary network about the convo- 

 luted tubules, and the straight capillaries of the medulla. 

 Sketch a portion of the cortex and medulla seen under low 

 power. 



(d) Human Kidney. 



A human kidney was cut transversely into flat pieces about } 

 of an inch thick, hardened in mercuric chloride, embedded in par- 

 affin, and sectioned. The sections were fixed to cover glasses, stained 

 in hsematoxylin and eosin, dehydrated, and cleared in oil of her- 

 gamot and xylol. Mount on balsam. 



Study under low power. Observe the relatively thick 

 capsule of fibrous tissue, and a narrow zone of convoluted 

 tubules just below the capsule, in which no Malpighiaii 

 corpuscles are found. Locate the medullary rays of the 

 cortex; between these are the portions of the uriniferous 

 tubules constituting the labyrinth of the kidney. Note the 

 scarcity of the connective tissue between the tubules ; also 

 the interlobular vessels passing up between the medullary 

 rays. In the medullary portion the collecting tubules con- 

 verge toward the apex of the Malpighian pyramid. The 

 largest ones near the apex of the pyramid are known as the 

 tubules of Bellini. Between the straight collecting tubules, 

 capillaries often filled with blood are to be looked for. 

 Sketch a portion of the cortex and of the medulla as seen 

 under high power, reproducing as accurately as possible 

 the character of the epithelium lining the different parts of 

 the uriniferous tubules. 



(e) Suprarenal Body. 



The suprarenal body of a guinea pig was hardened in mercuric 

 chloride, stained in Delafield's hsematoxylin, embedded in par- 

 affin, and sectioned. Fix and mount in balsam. 



Study first under low power. Observe the fibrous 

 capsule from which septa pass into the gland. The gland 



